Last modified: 2011-03-13 18:05:13 UTC
When attempting to place a restriction on a whole IP range (which someone said they would like to be able to do on http://en.wikipedia.org/wiki/Wikipedia:Administrators%27_noticeboard#Ability_to_block_users_from_specific_pages.2Fnamespaces_likely_coming ), the Special:RestrictUser page appears to give a "User not found" error.
The feature doesn't even exist any more per r41405.
OK, for IPv4, only 1 IP is restricted. But for IPv6, the minimum granularity should be a 64-bit range (for IPv6 addresses assigned to customers) and possibly smaller only for IPv6/IPv4 tunnels (like those initiated through Teredo and 6to4 servers, unless you restrict them like the proxies they really are)